This invention relates generally to mattresses and cushions and particularly to a mattress comprising of a plurality of foam layers and a pair of support members in one of the foam layers.
The mattress according to the invention provides side support that reduces the likelihood that a person will accidentally roll off and also provides increased comfort to a person sitting on the side of the mattress. Accordingly, a mattress according to the invention comprises a top layer formed to comprise a viscoelastic foam material having a first indentation load deflection rating and an upper surface and a lower surface and first and second sides. The mattress further comprises a buffer layer adjacent the lower surface of the top layer. The buffer layer is formed to comprise a foam material having a second indentation load deflection rating that is greater than the first indentation load deflection rating. The mattress also comprises a bottom layer arranged such that the buffer layer is between the top and bottom layers. The bottom layer preferably is formed to comprise a foam material having a third indentation load deflection rating that is greater than the second indentation load deflection rating. The mattress according to the invention has a first support member placed adjacent the first side of the top layer and the buffer layer and a second support member placed adjacent the second side of the top layer and the buffer layer. The first and second support members are firmer than the top layer and are arranged to support the top layer and provide reduced compression of the mattress when a weight is placed on the upper surface of the top layer near the support members.
The top layer preferably is arranged to form first and second elongate wedge-shaped cavities between the first and second sides of the top layer and adjacent regions of the buffer layer. The first and second support members preferably comprise elongate wedge-shaped high resiliency foam structures positioned within the first and second cavities, respectively.
The mattress first and second support members preferably have corresponding first and second outer edge portions arranged to have a thickness such that they extend from the upper surface of the top layer to the buffer layer.
The top layer preferably has a 25% indentation load deflection rating of about 13, the buffer layer preferably has a 25% indentation load deflection rating of about 26, the bottom layer preferably has a 25% indentation load deflection rating of about 32 and each of the first and second support members preferably has a 25% indentation load deflection rating of about 32.
The features of the invention may be more fully understood, and appreciated by referring to the drawings described briefly below and by referring to the detailed description of the invention.